This application claims the priority of DE 10326366.7 filed Jun. 12, 2003, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a cellular actuator device. Especially preferred embodiments of the invention relate to a cellular actuator device for actuating a control surface of an aircraft or spacecraft.
Conventionally, hydraulic actuators are predominantly used for actuating control surfaces of aircraft or spacecraft, such as control surfaces or trimming surfaces which are provided in a wing or in a fin an aircraft or spacecraft, particularly of an airplane. As a rule, these comprise of cylindrical hydraulic pistons which cause a displacement in the form of a linear movement between two control points.
When this wide-spread concept of the hydraulic cylinder is used for applications in which the linear movement is to be carried out on a broader surface, additional mechanical auxiliary constructions are required. A classical example is the actuation of a control surface of an airplane. As illustrated in FIG. 1, for the directional control of an airplane, for example, as a rule, a stationary vertical fin 2 and a rudder 3, which can be moved relative to the fin 3, are provided. The rudder 3 is rotatably disposed on the vertical fin 2 by means of a hinge 4 consisting of several joints and can be actuated by means of a hydraulic cylinder 5. The joints of the hinge 4 hold the vertical fin 2 and the rudder 3 against one another and have the result that the rudder 3 can carry out only movements about the joint axis with respect to the fin 2. The hydraulic cylinder 5 connects the fin 2 and the rudder 3 by way of a lever arm 5a, which is only outlined in the figure, and thereby can, on the one hand, absorb the torsional moment about the joint axis occurring because of the rudder loading and, on the other hand, cause an adjustment of the rudder 3 with respect to the fin 2. For reasons relating to the fail-safe characteristic, redundant hydraulic systems are often required, which is achieved by a combination of several hydraulic cylinders on one rudder. In this case, additional complex measures are required for ensuring the operability also during the blockage of one of the hydraulic cylinders.
It is a significant disadvantage that the loads are distributed on the rudder and the fin in a planar manner but can be transmitted only locally by way of the joints and the hydraulic cylinder or cylinders between the two components. The structure of the fin and the rudder therefore has to be reinforced such that the loads building up on the surface as a result of the aerodynamic stress and the mass loads can be guided to the local force introduction sites, specifically the joints and the fastening points of the hydraulic cylinder or cylinders. The above explanations on the example of a rudder of an airplane analogously apply to most control surfaces of an aircraft or spacecraft.
It is an object of the invention to provide an improved actuator device which is capable of absorbing loads distributed in a planar manner.
According to an aspect of the invention, this object is achieved by providing a cellular actuator device having a number of elementary cells, which are combined to a common arrangement and are formed by pressure-tight chambers, which elementary cells can be acted upon by a pressure medium and, when acted upon by the pressure medium, can be deformed in at least one work direction while changing their length, wherein the elementary cells are coupled for combining their length changes in the at least one working direction to an overall movement of the elementary cell arrangement.
Advantageous embodiments and further developments of cellular actuator devices according to preferred embodiments of the invention are described herein and in the claims.
The invention provides a cellular actuator device having a number of elementary cells combined to a joint arrangement and formed by pressure-tight chambers, which elementary cells can be acted upon by a pressure medium and, when being acted upon by the pressure medium, can be deformed while changing their length in at least one working direction, the elementary cells, for the combination of their length changes, being coupled in the at least one working direction to an overall movement of the elementary cell arrangement.
A significant advantage of the cellular actuator device according to the invention is the fact that it can be provided in a planar, largely arbitrarily curved or also cylindrical or spherical arrangement. In this case, the elementary cells each take over a part of the function of the entire actuator device. Advantageously, hydraulic liquid or a gas, such as air can be used as the pressure medium.
According to certain preferred embodiments of the cellular actuator device, the elementary cells can each contain a single pressure-tight chamber.
According to certain preferred embodiments of the invention, when the pressure-tight chambers are acted upon by pressure medium, the elementary cells may be deformable in a contracting manner in the working direction while changing their length.
According to certain preferred embodiments of the invention, when the pressure-tight chambers are acted upon by the pressure medium, the elementary cells may be deformable in an expanding manner in the working direction while changing their length.
According to certain preferred embodiments of the invention, the elementary cells may each contain at least one first pressure-tight chamber and at least one second pressure-tight chamber. In this case, it is particularly advantageous, when the (here thus defined) first pressure-tight chambers are acted upon, for the elementary cells to be deformable in a contracting manner in the working direction while their length is changed.
Correspondingly, it may further be provided in certain preferred embodiments of the invention, that, when the (here thus defined) second pressure-tight chambers are acted upon, the elementary cells can be deformed in an expanding manner in the working direction while changing their length.
Advantageously according to certain preferred embodiments of the invention, the (first) pressure-tight chambers have an essentially convex cross-sectional shape in the direction parallel to the working direction, an action by means of the pressure medium, while reinforcing the convexity of the pressure-tight chambers, causing an enlargement of the extension transversely to the working direction and a contraction in the working direction.
Advantageously according to certain preferred embodiments of the invention, on the other hand, the (second) pressure-tight chambers have an essentially concave cross-sectional shape in the direction parallel to the working direction, an action by means of the pressure medium, while decreasing the concavity of the pressure-tight chambers, causing an enlargement of the extension transversely to the working direction and an expansion in the working direction.
According to certain preferred embodiments of the invention, the pressure-tight chambers are preferably delimited by ends, which are mutually opposite in the working direction, and by side walls extending between the ends, and upper and lower cover walls sealing off the chambers on their top side and their bottom side.
In this case, it is particularly advantageous for the side walls of the pressure-tight chambers to be divided at half their extension between the ends and for the parts of the side walls to be are mutually connected there in an articulated manner, particularly by means of a solid-state joint.
According to certain preferred embodiments of the invention, the upper and/or lower cover walls can be formed by outwardly convex domes.
According to other certain preferred embodiments of the invention, the upper and/or lower cover walls can be formed by inwardly convex domes.
According to other certain preferred embodiments of the invention, the upper and/or lower cover walls can be formed by rigid cover plates and can be sealed off by sealing elements acting between the side walls and the rigid cover plates.
According to certain preferred embodiments of the invention, the pressure-tight chambers may have an essentially acute course at their ends which are mutually opposite in the working direction.
According to certain preferred embodiments of the invention, the pressure-tight chambers may have more or less expanded end surfaces at their ends which are mutually opposite in the working direction.
According to certain preferred embodiments of the invention, the elementary cells may be deformable in a working direction while changing their length.
According to certain preferred embodiments of the invention, the elementary cells may be deformable in at least two working directions while changing their length.
The elementary cell arrangement is preferably two-dimensional according to certain preferred embodiments of the invention.
According to certain preferred embodiments of the invention, the elementary cells may be arranged in a matrix-like arrangement parallel side-by-side and above one another in lines and columns.
As an alternative according to certain preferred embodiments of the invention, the elementary cells may be arranged in a honeycomb-type arrangement in an offset manner side-by-side and above one another.
Preferably passage ducts are provided between respective chambers which can be jointly acted upon by the pressure medium, according to certain preferred embodiments of the invention.
The actuator device may be provided for actuating a control surface of an aircraft or spacecraft according to certain preferred embodiments of the invention.
In particular, according to certain preferred embodiments of the invention, the actuator device can be provided as a planar actuator for actuating a rudder surface or trim surface of a shape-variable wing or of a shape-variable fin of an aircraft or spacecraft, particularly of an airplane.
The invention also relates to methods of making and using the respective cellular actuator devices.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.